LXR linux/fs/gfs2/acl.c

   1/*
   2 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
   3 * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
   4 *
   5 * This copyrighted material is made available to anyone wishing to use,
   6 * modify, copy, or redistribute it subject to the terms and conditions
   7 * of the GNU General Public License version 2.
   8 */
   9
  10#include <linux/sched.h>
  11#include <linux/slab.h>
  12#include <linux/spinlock.h>
  13#include <linux/completion.h>
  14#include <linux/buffer_head.h>
  15#include <linux/xattr.h>
  16#include <linux/posix_acl.h>
  17#include <linux/posix_acl_xattr.h>
  18#include <linux/gfs2_ondisk.h>
  19
  20#include "gfs2.h"
  21#include "incore.h"
  22#include "acl.h"
  23#include "xattr.h"
  24#include "glock.h"
  25#include "inode.h"
  26#include "meta_io.h"
  27#include "trans.h"
  28#include "util.h"
  29
  30static const char *gfs2_acl_name(int type)
  31{
  32        switch (type) {
  33        case ACL_TYPE_ACCESS:
  34                return GFS2_POSIX_ACL_ACCESS;
  35        case ACL_TYPE_DEFAULT:
  36                return GFS2_POSIX_ACL_DEFAULT;
  37        }
  38        return NULL;
  39}
  40
  41struct posix_acl *gfs2_get_acl(struct inode *inode, int type)
  42{
  43        struct gfs2_inode *ip = GFS2_I(inode);
  44        struct posix_acl *acl;
  45        const char *name;
  46        char *data;
  47        int len;
  48
  49        if (!ip->i_eattr)
  50                return NULL;
  51
  52        name = gfs2_acl_name(type);
  53        if (name == NULL)
  54                return ERR_PTR(-EINVAL);
  55
  56        len = gfs2_xattr_acl_get(ip, name, &data);
  57        if (len < 0)
  58                return ERR_PTR(len);
  59        if (len == 0)
  60                return NULL;
  61
  62        acl = posix_acl_from_xattr(&init_user_ns, data, len);
  63        kfree(data);
  64        return acl;
  65}
  66
  67int gfs2_set_acl(struct inode *inode, struct posix_acl *acl, int type)
  68{
  69        int error;
  70        int len;
  71        char *data;
  72        const char *name = gfs2_acl_name(type);
  73
  74        BUG_ON(name == NULL);
  75
  76        if (acl->a_count > GFS2_ACL_MAX_ENTRIES(GFS2_SB(inode)))
  77                return -E2BIG;
  78
  79        if (type == ACL_TYPE_ACCESS) {
  80                umode_t mode = inode->i_mode;
  81
  82                error = posix_acl_equiv_mode(acl, &mode);
  83                if (error < 0)
  84                        return error;
  85
  86                if (error == 0)
  87                        acl = NULL;
  88
  89                if (mode != inode->i_mode) {
  90                        inode->i_mode = mode;
  91                        mark_inode_dirty(inode);
  92                }
  93        }
  94
  95        if (acl) {
  96                len = posix_acl_to_xattr(&init_user_ns, acl, NULL, 0);
  97                if (len == 0)
  98                        return 0;
  99                data = kmalloc(len, GFP_NOFS);
 100                if (data == NULL)
 101                        return -ENOMEM;
 102                error = posix_acl_to_xattr(&init_user_ns, acl, data, len);
 103                if (error < 0)
 104                        goto out;
 105        } else {
 106                data = NULL;
 107                len = 0;
 108        }
 109
 110        error = __gfs2_xattr_set(inode, name, data, len, 0, GFS2_EATYPE_SYS);
 111        if (error)
 112                goto out;
 113
 114        if (acl)
 115                set_cached_acl(inode, type, acl);
 116        else
 117                forget_cached_acl(inode, type);
 118out:
 119        kfree(data);
 120        return error;
 121}
 122